What is Flex ?

Flex typically refers to a way of developing flash platform application using the components in the open source framework developed by adobe.

Flex applications are written as a combination of xml markup (mxml) and actionscript much in the same vein that html applications are written with JS. The big difference is that the output of all your mxml and actionscript files is a single swf that can be embedded in a web page and displayed to the world. You can also use Flex to develop AIR applications, applications that can be installed on a users desktop.

Flex is a free, open source framework for building highly interactive, expressive web applications that deploy consistently on all major browsers, desktops, and operating systems.

Flex provides a modern, standards-based language and programming model that supports common design patterns.

MXML, a declarative XML-based language, is used to describe UI layout and behaviors, and the object-oriented ActionScript® 3.0 programming language is used to create client logic.

Flex also includes a rich component library with more than 100 proven, extensible UI components for creating rich Internet applications (RIAs), as well as an interactive Flex application debugger.